1. Field of the Invention
The present invention relates to internal combustion engines, and to mechanisms for coupling removable utilitarian devices to be driven by an engine.
2. Description of the Related Art
Many types of power equipment, such as walk-behind and riding lawnmowers, utilize an internal combustion engine which has a vertically oriented crankshaft. The crankshaft rotates about a vertical axis when driven by one or more pistons which move within horizontal bores in the engine block. The crankshaft projects from the bottom of the engine where the implement being driven is attached. For a walk-behind lawnmower, a blade is attached to the lower end of the engine crankshaft and, for a riding lawnmower, a pulley or sprocket often is connected to that end of the crankshaft to drive the blades and wheels. The upper end of the vertical crankshaft typically connects to a flywheel and starter mechanism and does not extend out of the engine housing.
In some power equipment, it is desirable that the engine also power utilitarian devices, in addition to the primary implements, such as the blade and wheels of a lawnmower. Heretofore, the common technique employed by these and other types of power equipment was to drive such utilitarian devices from a coupling attached to the bottom end of the engine's crankshaft. For example, U.S. Pat. No. 6,155,035 describes a power take-off which couples the engine of a walk-behind lawnmower to a chipper-shredder placed alongside. U.S. Pat. No. 4,965,990 discloses attachment of an edger assembly to a walk-behind lawnmower. Thus all the equipment driven by the engine receive power from that same end of the crankshaft.
After an engine has been assembled unto a piece of power equipment, such as a lawnmower, it may be extremely difficult for a user to attach utilitarian devices that require power from the engine. Manufacturers often mount the engine on the frame of the equipment in such a manner where access to the lower end of the crankshaft is difficult or impossible. Unless the power equipment manufacturer provides a power take-off coupling, additional accessories often cannot be connected to the engine. Even when a power take-ff coupling is provided, it often requires exposed belts, chains or shafts which present a safety hazard.
In addition to lawnmowers, there are a variety of other equipment, such as electrical generators, power washers, vacuums, air compressors and chipper-shredders, that are driven by gasoline powered internal combustion engines. Heretofore each different piece of equipment had it own dedicated engine which added to the expense of the equipment. Cost savings could be achieved by designing a cart with a generic portable internal combustion engine to which different types of equipment can be interchangeably connected. For example, this enables a user to attach an electrical generator to the engine when power is needed at a remote location and at other times attach a pump or air compressor to the engine when those devices are needed.
Therefore, it is desirable to provide mechanism for interchangeably mounting a variety of utilitarian devices to an internal combustion engine in a manner that enables the devices to be exchanged easily by a user.